This invention relates to the field of compacts intended to contain cosmetics or beauty products, typically makeup powder.
As a general rule, compacts typically comprise:
a hollow lid fitted with an inner mirror,
a hollow base, typically equipped with a grid or intermediate support of at least one recipient intended to receive said cosmetic,
a hinge, forming the connection between said lid and said base, enabling the articulation of said lid and the opening of said compact,
a clasp or any locking and unlocking means of said lid in relation to said base, so as to ensure the opening and closing of said compact, a clasp typically comprising a push button.
Numerous embodiments of compacts are known, which may relate to one or more components of the compact.
In this way, in relation of the patents in the applicant""s name, it is possible to mention:
patent FR 2 661 080 which describes a small class makeup compact,
patent FR 2 701 365 which describes a convertible makeup compact,
patent FR 2 725 958 which relates an assisted opening joined closure compact,
patent FR 2 737 192 which describes a pivoting lid compact equipped with a flexible tabbed hinge,
patent FR 2 755 352 which describes a compact with assisted opening,
patent FR 2 755 353 which describes a compact with an unlocking and pre-opening push button,
patent FR 2 756 155 which describes a makeup compact comprising a base, an intermediate plate and a lid fitted with an inner mirror.
In addition, the French application No. 2 761 243 relating to a tight closure compact for cosmetics is known.
The compacts according to the state of the art are typically suitable to be filled with powders in a form which is relatively inert and stable over time.
However, increasingly, manufacturers are offering powders with a more complex formulation, which may, for this reason, comprise a volatile product.
Therefore, it has become essential to be able to manufacture tight compacts, i.e. compacts which, once closed, lose little or no volatile product, at least over a period which is at least equivalent to the average service life of said compacts.
Moreover, the tightness must be obtained without modifying the appearance of the compact significantly, particularly once open.
In addition, the means introduced to seal the compacts must not generate a marked additional cost, with reference to standard compacts, meaning that said means must be inherently simple and that the manufacture of the different parts, their assembly and assembly rates and the materials forming these different parts, must be approximately those already used in the art.
Finally, in the field of compacts in particular, product range renewal is continuously required, as is product personalisation.
According to the invention, the compact intended to be filled with cosmetics comprises a lid, generally fitted with a mirror, a hollow base typically comprising, possibly using an intermediate grid attached to said base, a recipient intended to receive said cosmetics, a hinge and a clasp, comprises xe2x80x9cupperxe2x80x9d sealing means attached to said lid and xe2x80x9clowerxe2x80x9d sealing means attached to said base or, if applicable, to said grid or said recipient, said sealing means co-operating when said compact is closed, and is characterised in that:
a) each of the xe2x80x9cupperxe2x80x9d and xe2x80x9clowerxe2x80x9d sealing means comprise a typically vertical skirt, referred to as xe2x80x9cupperxe2x80x9d and xe2x80x9clowerxe2x80x9d respectively,
b) said tight co-operation is a tangential connection of said xe2x80x9cupperxe2x80x9d and xe2x80x9clowerxe2x80x9d skirts, with an angle xcex1 between 45xc2x0 and 90xc2x0,
c) at least one of said xe2x80x9cupperxe2x80x9d or xe2x80x9clowerxe2x80x9d skirts is a flexible skirt and shows an elasticity or reversible deformability under stress, such that said tangential connection induces said deformation of at least said flexible skirt by reaction along a direction typically perpendicular to the angle xcex1,
d) masking means, typically rigid and attached to said compact, border, and possibly surround, at least one of said skirts, and typically said flexible skirt, over all or part of its height, at a distance from said skirt enabling all or part of said reversible deformation of said flexible skirt,
so as to obtain a tight compact with sealing means, which firstly are completely or partially masked and secondly enable great freedom in terms of relative axial positioning and, as a result, standard precision for the parts forming said compact.
This combination of means solves the problems described. Indeed, the applicant has observed that a tight co-operation could be obtained with only one tangential connection of a relatively high slope of an angle xcex1 at least equal to 45xc2x0, and preferentially greater than 75xc2x0, such that said xe2x80x9cupperxe2x80x9d and xe2x80x9clowerxe2x80x9d skirts co-operate by sliding on each other with deflection of said flexible skirt to the position corresponding to the closed lid, where the deflection stress may remain constant during the closure of the lid when the angle xcex1 is around 90xc2x0, or increase slightly for a smaller angle xcex1.
Preferentially, the materials selected to implement this tight co-operation are plastics which show, in addition to sufficient resilience, a sufficiently smooth surface condition such that the friction coefficient is low and a sufficient surface hardness such that there is no premature wear of the sealing means due to friction of said upper and lower skirts; the hardness or rigidity of the materials should not be too high either so as not to create sealing problems.
According to the invention, said tangential connection must preferentially form a strip, which is closed on itself, but narrow in width, typically less than 3 mm wide, and preferentially less than 1 mm wide, such that the deflection stress created by said tight co-operation creates a local pressure which increases as the width of the strip decreases, and thus, ensure the tightness, possibly using localised plastic flow in the event of a very high local concentration of deflection stress, due to irregular dimensions.
In this way, contrary to expectations, the means of the invention, although they are simple, are sufficient to obtain the required tightness.
According to a theory suggested by the applicant, this may be due to the actual design of said tight cooperation according to the invention, and particularly due to the fact that the upper and lower skirts never come to a stop against any surfaces, the ends being free in terms of axial movement. However, if the end of a flexible skirt came to a stop and was blocked, it can be assumed that a compression stress would appear in the skirt, which would probably affect the deflection stress and reduce its effectiveness.
In addition, in practical terms, the fact that a deflection stress is sufficient to ensure tightness means that it is possible to have, for the parts forming the sealing means, a manufacturing precision, typically by moulding, which is the same as that for standard parts, which represents a major advantage of the invention. Indeed, tightness is obtained by the existence of a tangential deflection stress over the entire skirt perimeter, and which is applied over a relatively large axial distance, typically of several mm, which therefore allows the system a degree of freedom in the axial direction.